Barycentric clipping in the renderer and flat shading

Summary:
Updates to the Renderer to enable barycentric clipping. This is important when there is blurring in the rasterization step.

Also added support for flat shading.

Reviewed By: jcjohnson

Differential Revision: D19934259

fbshipit-source-id: 036e48636cd80d28a04405d7a29fcc71a2982904

tests/test_rendering_utils.py

@@ -0,0 +1,64 @@
+#!/usr/bin/env python3
+# Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.
+
+
+import unittest
+import torch
+
+from pytorch3d.renderer.utils import TensorProperties
+
+from common_testing import TestCaseMixin
+
+
+# Example class for testing
+class TensorPropertiesTestClass(TensorProperties):
+    def __init__(self, x=None, y=None, device="cpu"):
+        super().__init__(device=device, x=x, y=y)
+
+    def clone(self):
+        other = TensorPropertiesTestClass()
+        return super().clone(other)
+
+
+class TestTensorProperties(TestCaseMixin, unittest.TestCase):
+    def test_init(self):
+        example = TensorPropertiesTestClass(x=10.0, y=(100.0, 200.0))
+        # Check kwargs set as attributes + converted to tensors
+        self.assertTrue(torch.is_tensor(example.x))
+        self.assertTrue(torch.is_tensor(example.y))
+        # Check broadcasting
+        self.assertTrue(example.x.shape == (2,))
+        self.assertTrue(example.y.shape == (2,))
+        self.assertTrue(len(example) == 2)
+
+    def test_to(self):
+        # Check to method
+        example = TensorPropertiesTestClass(x=10.0, y=(100.0, 200.0))
+        device = torch.device("cuda:0")
+        new_example = example.to(device=device)
+        self.assertTrue(new_example.device == device)
+
+    def test_clone(self):
+        # Check clone method
+        example = TensorPropertiesTestClass(x=10.0, y=(100.0, 200.0))
+        new_example = example.clone()
+        self.assertSeparate(example.x, new_example.x)
+        self.assertSeparate(example.y, new_example.y)
+
+    def test_get_set(self):
+        # Test getitem returns an accessor which can be used to modify
+        # attributes at a particular index
+        example = TensorPropertiesTestClass(x=10.0, y=(100.0, 200.0, 300.0))
+
+        # update y1
+        example[1].y = 5.0
+        self.assertTrue(example.y[1] == 5.0)
+
+        # Get item and get value
+        ex0 = example[0]
+        self.assertTrue(ex0.y == 100.0)
+
+    def test_empty_input(self):
+        example = TensorPropertiesTestClass(x=(), y=())
+        self.assertTrue(len(example) == 0)
+        self.assertTrue(example.isempty())